Catheter



Dec. 31, "I D. E- WILLIAMSON CATHETER Filed Jan. 17, 1966 FIG. I

FIG. 2

FIG; 3

ATTORNEYS United States Patent O 3,419,010 CATHETER Donald E. Williamson, Miami, Fla., assignor to Cordis Corporation, Miami, Fla., a corporation of Florida Filed Jan. 17, 1966, Ser. No. 521,209 2 Claims. (Cl. 128-350) ABSTRACT OF THE DISCLOSURE A ventricular catheter which may be inserted into a position within the ventrical to conduct away fluid without clogging consists of a flexible, resilient tubular body terminating in a tip portion which is itself normally curved in the shape of a hook, with drainage perforations situated on the inside of the hook. A stylet, preferably of smaller diameter and having a roughened surface inserted into the hook causes it to straighten for insertion.

This invention relates to catheters for continuous drainage of fluids from cavities of the body, such as catheters of the implantable kind for the drainage of cerebrospinal fluid from the cerebral ventricles.

In the treatment of cases of hydrocephalus and similar conditions, where there is difiiculty in the free circulation and absorption of the cerebrospinal fluid, drainage systems are in use in which a ventricular catheter is implanted in the ventricle, the catheter serving for the transmission of fluid, via the internal or external jugular vein, to the atrium of the heart. However, problems have arisen in such catheterization such as the accurate positioning of the catheter Within the ventricles and its maintainance in that position, the prevention of clogging of the orifices at the tip of the catheter during and after implantation, and, in the implantation procedure itself, the manipulation of a catheter of flexible material.

It is the general purpose of this invention to provide a catheter which solves the above problems. A novel form of catheter is shown in which the distal end is formed into a curve. One or more holes are placed in the inside of the curve to permit suitable flow of fluid into or out of the lumen of the catheter. With the holes in this position, the catheter may lie in any position against the soft tissue lining the fluid-filled cavity without the slightest possibility that the hole can come in contact with the wall in such a manner that it will be obstructed as described above.

Therefore one of the objects of this invention is the provision of a catheter of resilient material for fluid drainage, which maybe held in a substantially rigid form during the implantation, but which thereafter resumes its flexibility.

Another object is the provision of a catheter for the purpose of drainage, of fluids which presents a minimum likelihood of clogging, both during the implantation and afterwards.

A further object of the invention is the provision of a catheter with means incorporated therein to assist in properly locating the drainage tip of the catheter within a cavity and to maintain the catheter in the selected position.

Finally, the provision of a catheter of the above classes and for the stated use, which is economical to manufacture and relatively simple to use.

Other objects and advantages will be in part obvious and in part pointed out hereinafter.

In the accompanying drawings, in which is illustrated one embodiment of the invention:

FIG. 1 is an elevation, partly in section, of the tip portion of a catheter of this invention;

FIG. 2 is a portion of the FIG. 1 embodiment, partly CJI ice

in section, showing the combination thereof with a straight stylet preparatory to implantation;

FIG. 3 is a schematic view of a ventricle showing a first position of the catheter of this invention after implantation;

FIG. 4 is a view similar to FIG. 3 but showing a second position of the catheter; and

FIG. 5 is a view of a portion of the catheter to show the shape of an orifice therein.

Throughout the drawings, similar reference characters indicate corresponding parts. Portions of the drawings have been relatively enlarged, in some instances, for the purposes of clarity.

Turning now to FIG. 1, the tip portion, generally indicated by numeral 2, of a catheter is shown in elevation, the catheter comprising a tube made, for example, of a resilient flexible material such as silicone rubber. Only the tip portion of the catheter is shown, and it is obvious that the catheter can be made in any length desired for the purposes of facilitating the trimming of the catheter to the correct length after implantation. The tip portion is curved, as shown, in the form of a hook for reasons given below, but it will be noted that the distal end portion indicated by the bracket 5 is straight, In this embodiment, the end 4 of the catheter is closed, and has a bulletshaped nose at the very end to facilitate its penetration into the brain tissue. For other purposes, end 4 might be left open. The wall 6 of the curved portion of the catheter tip which lies on the inside of the curve is provided with a series of holes 8 for drainage purposes. These holes may be circular in shape if desired, but it is preferred that they be generally oval or ellipsoidal (see FIG. 5) in crosssection with the long axis of the oval lying parallel to the axis of the catheter rather than lying across it. In this way, sufficiently large orifices can be used without the side edges of the orifices extending below the median plane of the catheter. Three orifices are shown, but more or fewer orifices can be used, if desired.

Referring to FIG. 2, there is shown the tip of the FIG. 1 embodiment which has had inserted therein the rigid stylet 12. Stylet 12 is made slightly smaller in diameter than the lumen of the catheter in order to permit the outward flow of fluid between the catheter itself and the stylet, during an insertion, as a means of indicating that the end of the catheter has entered a fluid-filled cavity. The stylet is also roughened on its surface to minimize any tendency of the stylet to stick to the material of the catheter itself. Roughing can be done by conventional abrading means, or by electro-etching. When the stylet 12 is inserted in the lumen of the catheter, the catheter will straighten in order to follow the configuration or curvature (straight in this embodiment) of the stylet. The end of the stylet 14 may be rounded, as shown, in order to facilitate insertion of the stylet in the catheter. The function of the straight section 5 now becomes apparent. Since the stylet 12 is smaller in diameter than the lumen of the catheter, the section 5 prevents any exaggerated canting or cocking of the end of the tip of the catheter due to the effort of the catheter to return to its original shape.

Prior to implementation, the stylet is inserted in the catheter in order to straighten the tip portion thereof, and then the straightened tip portion of the catheter, held so by the stylet, is easilp guided into the proper location At this point, fluid from the cavity will flow out through the catheter, since the stylet 12 does not fill the catheter completely. The stylet is then removed, with the result that the catheter resumes its hook shape. This result and position are shown in FIG. 3, where the wall of the cavity is indicated by numeral 16. At this point, the catheter may be left in position as shown in FIG. 3, or it preferably may be withdrawn until the end 4 of the tip comes in contact with the wall of the cavity (see FIG. 4), thus indicating to the surgeon where the tip 01 the catheter is located. Thereafter, the surgeon can position the catheter as he desires. Also, the curvature of the catheter provides a means of locating the far wall of the cavity. By properly anchoring the outer end of the catheter, the catheter will now be held in the position selected by the surgeon. It will be noted that because of the curved shape of the catheter and the fact that the holes 8 are in the inside wall of this curvature, the catheter can lie in any position against the soft tissue lining the fiuidfilled cavity without the holes 8 coming in such contact with that tissue that they will be closed off.

It has been indicated that the catheter can be made of silicone rubber, but other flexible materials can be used which are not eifected by the cerebrospinal fluids or by the surrounding tissue, and, of course, are tolerated by the body. The material should be such as being capable of retaining the curved form shown in FIG. 1 during use, but being flexible enough so as to be straightened by the stylet 12. In addition to the above, the material of the catheter should, of course, be such as to be sterilized without damage thereto. The stylet 12 can be made, for example, of stainless steel.

While the catheter of this invention has been described with particular reference to its use in draining cerebral ventricles, it will be apparent that the advantages set forth above will also be present in the use of the catheter for the drainage of other body cavities such as the bladder or pleura.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

As many changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense, and it is also intended that the appended claims shall cover all such equivalent variations as come within the true spirit and scope of the invention.

Having thus described my invention, What I claim as new and desire to secure by Letters Patent of the United States is:

1. A cerebro ventricular catheter insertable through brain tissue for the drainage of cerebro spinal fluid having proximal and distal ends and consisting of a flexible resilient tubular body of elastomeric material terminating at the distal end in a tip portion which is itself initially curved in the shape of a hook and normally retains its curved hooked shape solely through its resilience and being adapted to be straightened solely by the insertion of a stylet therein, the portion of the wall of said tip portion lying on the inside of the hook being perforated, and said perforations being externally unobstructed when the catheter is straightened by the stylet therein, whereby said catheter prior to penetration through brain tissue can be straightened by insertion of the stylet, and said hooked portion may be moved Within the cerebro ventricular cavity to probe the dimensions thereof.

2. A cerebro ventricular catheter as defined by claim 1 in combination with the stylet therein, said stylet having a diameter smaller than the internal diameter of the catheter.

References Cited UNITED STATES PATENTS 2,164,926 7/ 1939 Kleine 128349 2,230,226 2/1941 Auzin l28349 2,393,003 1/1946 Smith 128-349 FOREIGN PATENTS 707,333 4/1931 France. 580,008 7/1958 Italy.

DALTON L. TRULUCK, Primary Examiner. 

